A pseudanthium ( Ancient Greek for 'false flower'; pl. : pseudanthia ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads , composite flowers , or capitula , which are special types of inflorescences in which anything from a small cluster to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthia take various forms. The real flowers (the florets) are generally small and often greatly reduced, but the pseudanthium itself can sometimes be quite large (as in the heads of some varieties of sunflower ).
43-488: Carlina is a genus of flowering plants in the family Asteraceae . It is distributed from Madeira and the Canary Islands across Europe and northern Africa to Siberia and northwestern China. Plants of the genus are known commonly as carline thistles . Carlina species are very similar to true thistles (genus Cirsium ) in morphology , and are part of the thistle tribe, Cardueae . Most are biennial herbs, but
86-456: A dandelion , commonly blown on by children, consists of numerous seeds resting on the receptacle, each seed attached to its pappus. The pappi provide a parachute-like structure to help the seed travel from its point of origin to a more hospitable site. A ray flower is a two- or three-lobed, strap-shaped, individual flower, found in the head of most members of the Asteraceae. The corolla of
129-460: A bract, called a "palea" or "receptacular bract". These bracts are often called " chaff ". The presence or absence of these bracts, their distribution on the receptacle, and their size and shape are all important diagnostic characteristics for genera and tribes. The florets have five petals fused at the base to form a corolla tube and they may be either actinomorphic or zygomorphic . Disc florets are usually actinomorphic, with five petal lips on
172-399: A distance, each capitulum may appear to be a single flower. Enlarged outer (peripheral) flowers in the capitulum may resemble petals, and the involucral bracts may look like a calyx. In plants of the Asteraceae, what appears to be a single "daisy"-type flower is actually a composite of several much smaller flowers, known as the capitulum or head . By visually presenting as a single flower,
215-458: A dome-like structure called the receptacle . The individual florets in a head consist, developmentally, of five fused petals (rarely four); instead of sepals , they have threadlike, hairy, or bristly structures, known collectively as a pappus , (plural pappi ). The pappus surrounds the ovary and can, when mature and attached to a seed, adhere to animal fur or be carried by air currents, aiding in seed dispersal . The whitish, fluffy head of
258-488: A plant in the family Asteraceae. However, on-line botanical glossaries do not define it, and Google Scholar does not link to any significant usage of the term in a botanical sense. Pseudanthia occur in 40 plant families including: In some families, it is not yet clear whether the "flower" represents a pseudanthium because the anatomical work has not been done (or is still ambiguous due to considerable evolutionary reduction). Possible pseudanthia of this type may occur in
301-406: A polyaxial instead of a monoaxial configuration. The collection of independent organs into a complex structure is called synorganization . Head is an equivalent term for flower head and pseudanthium when used in the botanical sense. Capitulum (plural capitula ) can be used as an exact synonym for pseudanthium and flower head; however, this use is generally but not always restricted to
344-440: A related species. The essential oil of both species is mostly composed of carlina oxide, an acetylene derivative. The compound has antimicrobial activity. The young flowerhead of C. acaulis is also eaten like an artichoke . Asteraceae Asteraceae ( / ˌ æ s t ə ˈ r eɪ s i . iː , - ˌ aɪ / ) is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within
387-597: A whorl of bracts below the flowers, forming an involucre . In all cases, a pseudanthium is superficially indistinguishable from a flower, but closer inspection of its anatomy will reveal that it is composed of multiple flowers. Thus, the pseudanthium represents an evolutionary convergence of the inflorescence to a reduced reproductive unit that may function in pollination like a single flower, at least in plants that are animal pollinated. Pseudanthia may be grouped into types. The first type has units of individual flowers that are recognizable as single flowers even if fused. In
430-482: A widespread distribution, from subpolar to tropical regions , in a wide variety of habitats. Most occur in hot desert and cold or hot semi-desert climates , and they are found on every continent but Antarctica . Their common primary characteristic is compound flower heads , technically known as capitula , consisting of sometimes hundreds of tiny individual florets enclosed by a whorl of protective involucral bracts . The oldest known fossils are pollen grains from
473-553: Is a discoid head . Disciform heads possess only disc flowers in their heads, but may produce two different sex types (male or female) within their disciform head. Some other species produce two different head types: staminate (all-male), or pistillate (all-female). In a few unusual species, the "head" will consist of one single disc flower; alternatively, a few species will produce both single-flowered female heads, along with multi-flowered male heads, in their "pollination strategy". The distinguishing characteristic of Asteraceae
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#1732877189812516-414: Is a hairy cypsela with a plumelike pappus made up of tufts of bristles. Carlina is closely related to the genus Atractylis . Together they are a sister group to the genus Atractylodes in the subtribe Carlininae. Carlina has been divided into five subgenera: Carlina , Carlowizia , Heracantha , Lyrolepis , and Mitina . There are about 28 to 34 species in the genus. The genus name honors
559-533: Is an advantage in relatively dry zones, or some combination of these and possibly other factors. Heterocarpy, or the ability to produce different fruit morphs, has evolved and is common in Asteraceae. It allows seeds to be dispersed over varying distances and each is adapted to different environments, increasing chances of survival. The original name Compositae is still valid under the International Code of Nomenclature for algae, fungi, and plants. It refers to
602-1370: Is based on Panero & Funk (2002) updated in 2014, and now also includes the monotypic Famatinanthoideae . The diamond (♦) denotes a very poorly supported node (<50% bootstrap support), the dot (•) a poorly supported node (<80%). Barnadesioideae : 9 genera, 93 species. South America , mainly the Andes . Famatinanthoideae : South America, 1 genus, 1 species Famatinanthus decussatus . Mutisioideae : 58 genera, 750 species. Absent from Europe, mostly in South America. Stifftioideae : 10 genera. South America. Wunderlichioideae : 8 genera, 24 species. Mostly in Venezuela and Guyana . Gochnatioideae : 4 or 5 genera, 90 species. Latin America and southern United States. Hecastocleidoideae : Only Hecastocleis shockleyi . Southwestern United States . Carduoideae : 83 genera, 2,500 species. Worldwide. Pertyoideae : 5 or 6 genera, 70 species. Asia. Gymnarrhenoideae : Two genera/species, Gymnarrhena micrantha ( Northern Africa , Middle East ) and Cavea tanguensis ( Eastern Himalayas ). Cichorioideae : 224 genera, 3,200 species. Worldwide. Corymbioideae : Only
645-517: Is particularly common among the Cichorioideae . Leaves can be alternate , opposite , or whorled . They may be simple , but are often deeply lobed or otherwise incised, often conduplicate or revolute . The margins also can be entire or toothed . Resin or latex can also be present in the leaves. Nearly all Asteraceae bear their flowers in dense flower heads called capitula . They are surrounded by involucral bracts , and when viewed from
688-639: Is the strap-shaped tongue of the corolla of either a ray flower or of a ligulate flower. A disk flower (or disc flower ) is a radially symmetric individual flower in the head, which is ringed by the ray flowers when both are present. In some species, ray flowers may be arranged around the disc in irregular symmetry, or with a weakly bilaterally symmetric arrangement. A radiate head has disc flowers surrounded by ray flowers. A ligulate head has all ligulate flowers and no disc flowers. When an Asteraceae flower head has only disc flowers that are either sterile, male, or bisexual (but not female and fertile), it
731-404: Is their inflorescence , a type of specialised, composite flower head or pseudanthium , technically called a calathium or capitulum , that may look superficially like a single flower. The capitulum is a contracted raceme composed of numerous individual sessile flowers , called florets , all sharing the same receptacle . A set of bracts forms an involucre surrounding the base of
774-581: The Holy Roman Emperor Charles V (1500–1558). Carlina species have been used as herbal remedies in European systems of traditional medicine . C. acaulis root is known as Carlinae radix and is still used medicinally as a diuretic and a treatment for such conditions as skin lesions and rashes, catarrh , and toothache . Most commercial preparations of Carlinae radix are not C. acaulis , but are in fact adulterated with C. acanthifolia ,
817-556: The Late Cretaceous ( Campanian to Maastrichtian ) of Antarctica, dated to c. 76–66 million years ago (mya). It is estimated that the crown group of Asteraceae evolved at least 85.9 mya (Late Cretaceous, Santonian ) with a stem node age of 88–89 mya (Late Cretaceous, Coniacian ). Asteraceae is an economically important family, providing food staples, garden plants, and herbal medicines. Species outside of their native ranges can become weedy or invasive . Members of
860-613: The order Asterales . The number of species in Asteraceae is rivaled only by the Orchidaceae , and which is the larger family is unclear as the quantity of extant species in each family is unknown. The Asteraceae were first described in the year 1740 and given the original name Compositae . The family is commonly known as the aster , daisy , composite , or sunflower family . Most species of Asteraceae are herbaceous plants , and may be annual , biennial , or perennial , but there are also shrubs , vines , and trees . The family has
903-410: The "composite" nature of the capitula, which consist of a few or many individual flowers. Flower head Pseudanthia are characteristic of the daisy and sunflower family ( Asteraceae ), whose flowers are differentiated into ray flowers and disk flowers, unique to this family. The disk flowers in the center of the pseudanthium are actinomorphic and the corolla is fused into a tube. Flowers on
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#1732877189812946-455: The "sun disk" is made up of smaller, radially symmetric , individual flowers called disc flowers or disc florets . The word aster means "star" in Greek, referring to the appearance of most family members as a " celestial body with rays". The capitulum, which often appears to be a single flower, is often referred to as a head . In some species, the entire head is able to pivot its floral stem in
989-479: The Asteraceae are mostly herbaceous plants, but some shrubs, vines, and trees (such as Lachanodes arborea ) do exist. Asteraceae species are generally easy to distinguish from other plants because of their unique inflorescence and other shared characteristics, such as the joined anthers of the stamens . Nonetheless, determining genera and species of some groups such as Hieracium is notoriously difficult (see " damned yellow composite " for example). Members of
1032-538: The Asteroideae and other minor subfamilies these are usually borne only on florets at the circumference of the capitulum and have a 3+2 scheme – above the fused corolla tube, three very long fused petals form the ligule, with the other two petals being inconspicuously small. The Cichorioideae has only ray florets, with a 5+0 scheme – all five petals form the ligule. A 4+1 scheme is found in the Barnadesioideae. The tip of
1075-647: The apertures." In Asteraceae, the energy store is generally in the form of inulin rather than starch. They produce iso/ chlorogenic acid , sesquiterpene lactones , pentacyclic triterpene alcohols, various alkaloids , acetylenes (cyclic, aromatic, with vinyl end groups), tannins . They have terpenoid essential oils that never contain iridoids . Asteraceae produce secondary metabolites , such as flavonoids and terpenoids . Some of these molecules can inhibit protozoan parasites such as Plasmodium , Trypanosoma , Leishmania and parasitic intestinal worms, and thus have potential in medicine. Compositae,
1118-490: The capitulum functions in attracting pollinators , in the same manner that other "showy" flowering plants in numerous other, older, plant families have evolved to attract pollinators. The previous name for the family, Compositae , reflects the fact that what appears to be a single floral entity is in fact a composite of much smaller flowers. The "petals" or "sunrays" in an "asteraceous" head are in fact individual strap-shaped flowers called ray flowers or ray florets , and
1161-486: The capitulum. These are called "phyllaries", or "involucral bracts". They may simulate the sepals of the pseudanthium. These are mostly herbaceous but can also be brightly coloured (e.g. Helichrysum ) or have a scarious (dry and membranous) texture. The phyllaries can be free or fused, and arranged in one to many rows, overlapping like the tiles of a roof ( imbricate ) or not (this variation is important in identification of tribes and genera). Each floret may be subtended by
1204-455: The corolla, while the anthers are generally connate ( syngenesious anthers), thus forming a sort of tube around the style ( theca ). They commonly have basal and/or apical appendages. Pollen is released inside the tube and is collected around the growing style, and then, as the style elongates, is pushed out of the tube ( nüdelspritze ). The pistil consists of two connate carpels . The style has two lobes. Stigmatic tissue may be located in
1247-455: The course of the day to track the sun (like a "smart" solar panel), thus maximizing the reflectivity of the entire floral unit and further attracting flying pollinators. Nearest to the flower stem lie a series of small, usually green, scale-like bracts . These are known as phyllaries ; collectively, they form the involucre , which serves to protect the immature head of florets during its development. The individual florets are arranged atop
1290-422: The extant genus Dasyphyllum . Barreda, et al. (2015) estimated that the crown group of Asteraceae evolved at least 85.9 mya (Late Cretaceous, Santonian ) with a stem node age of 88–89 mya (Late Cretaceous, Coniacian ). It is not known whether the precise cause of their great success was the development of the highly specialised capitulum, their ability to store energy as fructans (mainly inulin ), which
1333-439: The family Asteraceae generally produce taproots , but sometimes they possess fibrous root systems. Some species have underground stems in the form of caudices or rhizomes . These can be fleshy or woody depending on the species. The stems are herbaceous, aerial, branched, and cylindrical with glandular hairs, usually erect, but can be prostrate to ascending. The stems can contain secretory canals with resin , or latex , which
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1376-401: The family Asteraceae. At least one source defines it as a small flower head. In addition to its botanical use as a term meaning flower head it is also used to mean the top of the sphagnum plant. Calathid (plural calathids or calathidia ) is a very rarely used term. It was defined in the 1966 book, The genera of flowering plants (Angiospermae) , as a specific term for a flower head of
1419-497: The fruit (for example in dandelion ). In some species, however, the pappus falls off (for example in Helianthus ). Cypsela morphology is often used to help determine plant relationships at the genus and species level. The mature seeds usually have little endosperm or none. The pollen of composites is typically echinolophate, a morphological term meaning "with elaborate systems of ridges and spines dispersed around and between
1462-549: The genus Corymbium , with 9 species. Cape provinces, South Africa. Asteroideae : 1,130 genera and 16,200 species. Worldwide. The family includes over 32,000 currently accepted species, in over 1,900 genera ( list ) in 13 subfamilies. The number of species in the family Asteraceae is rivaled only by Orchidaceae. Which is the larger family is unclear, because of the uncertainty about how many extant species each family includes. The four subfamilies Asteroideae , Cichorioideae , Carduoideae and Mutisioideae contain 99% of
1505-582: The genus includes annuals, perennials, shrubs , and dwarf trees , as well. The largest reach about 80 centimeters tall. The stems are upright and branching or unbranched. The whole plant is spiny . The leaves have toothed or lobed blades with spiny edges and sometimes woolly hairs. The flower heads are solitary or borne in inflorescences . The head is hemispherical to bell-shaped and lined with several layers of spiny phyllaries . The outer phyllaries may be very long and leaflike. It contains tubular or funnel-shaped disc florets in shades of yellow or red. The fruit
1548-444: The interior surface or form two lateral lines. The ovary is inferior and has only one ovule , with basal placentation . In members of the Asteraceae the fruit is achene -like, and is called a cypsela (plural cypselae ). Although there are two fused carpels, there is only one locule, and only one seed per fruit is formed. It may sometimes be winged or spiny because the pappus, which is derived from calyx tissue often remains on
1591-484: The ligule is often divided into teeth, each one representing a petal. Some marginal florets may have no petals at all (filiform floret). The calyx of the florets may be absent, but when present is always modified into a pappus of two or more teeth, scales or bristles and this is often involved in the dispersion of the seeds. As with the bracts, the nature of the pappus is an important diagnostic feature. There are usually four or five stamens . The filaments are fused to
1634-473: The original name for Asteraceae, were first described in 1740 by Dutch botanist Adriaan van Royen . Traditionally, two subfamilies were recognised: Asteroideae (or Tubuliflorae) and Cichorioideae (or Liguliflorae). The latter has been shown to be extensively paraphyletic , and has now been divided into 12 subfamilies, but the former still stands. The study of this family is known as synantherology . The phylogenetic tree of subfamilies presented below
1677-426: The periphery are zygomorphic and the corolla has one large lobe (the so-called "petals" of a daisy are individual ray flowers, for example). Either ray or disk flowers may be absent in some plants: Senecio vulgaris lacks ray flowers and Taraxacum officinale lacks disk flowers. The individual flowers of a pseudanthium in the family Asteraceae (or Compositae) are commonly called florets . The pseudanthium has
1720-434: The ray flower may have two tiny, vestigial teeth, opposite to the three-lobed strap, or tongue, indicating its evolution by fusion from an ancestral, five-part corolla. In some species, the 3:2 arrangement is reversed, with two lobes, and zero or three tiny teeth visible opposite the tongue. A ligulate flower is a five-lobed, strap-shaped, individual flower found in the heads of certain other asteraceous species. A ligule
1763-462: The rim of the corolla tube. The petal lips may be either very short, or long, in which case they form deeply lobed petals. The latter is the only kind of floret in the Carduoideae , while the first kind is more widespread. Ray florets are always highly zygomorphic and are characterised by the presence of a ligule , a strap-shaped structure on the edge of the corolla tube consisting of fused petals. In
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1806-463: The second type, the flowers do not appear as individual units and certain organs like stamens and carpels can not be associated with any individual flowers. The term pseudanthium was originally applied to flowers with stamens in two whorls with the outer whorl opposite the petals (obdiplostemonate) or polyandric flowers; by the early 1900s the term was repurposed by the advocates of the 'pseudanthium theory' which assumed flower evolution originated from
1849-499: The species diversity of the whole family (approximately 70%, 14%, 11% and 3% respectively). Because of the morphological complexity exhibited by this family, agreeing on generic circumscriptions has often been difficult for taxonomists . As a result, several of these genera have required multiple revisions. The oldest known fossils of members of Asteraceae are pollen grains from the Late Cretaceous of Antarctica , dated to ~76–66 mya ( Campanian to Maastrichtian ) and assigned to
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